Various explosively actuated cutting devices have been proposed heretofore for cutting cables, lines, wires and the like. Examples of such prior devices are disclosed in the following U.S. Pat. Nos. Matthews 2,687,572; Smyres 2,716,813; Gross 2,742,697; Temple 2,806,442; Bohl et al 2,924,147; Wilterdink et al 3,175,289; Temple et al 3,246,396; Parnell 3,393,605; and Giebel et al 3,886,842.
None of these prior devices was specifically intended for bomb disposal purposes by law enforcement authorities, who frequently are presented with emergencies in which a bomb, or what is apparently a bomb, must be disabled or blown up under safe conditions. In many such emergencies the indicated procedure is to sever an electrical wire, or pair of wires, on the bomb.
In the above-cited patents to Mattnews, Smyres, Parnell, Wilterdink at al, Temple et al, and Giebel et al, the piston has a straight wire-cutting edge extending transverse to the cable, line or wire to be cut. Consequently, after being severed, the cut ends of this cable, line or wire might be relatively close to each other, which could be disastrous if the wire being cut were part of the electrical wiring for a bomb and the severed wire ends touch each other or touch the casing of the wire cutter.
This is also true of the Temple patent, which has a cutting punch with a conical tip for severing the line.
In the Bohl et al patent the piston has a circular knife edge at its periphery. This is also true of the Gross patent, in which this cutting edge of the piston cooperates with a fixed sleeve inside the barrel which provides a female cutting die element. In both of these patents, therefore, the entire length of the wire segment which extends across the bore of the barrel is severed from the remainder of the wire. However, neither of these patents has provision for venting the explosion gases in such a manner that they blow the severed ends away from the cutting device to positively prevent the inadvertent closing of an electrical circuit through the wire or the like which has just been cut.